长效油菜素内酯TS303和二氢茉莉酸丙酯协同提高大豆光合能力

Synergistic Effects of Long-lasting Brassinosteroid TS303 and Prophyl Dihydrojasmonate on Enhancing Photosynthetic Capacity of Soybean

研究了长效油菜素内酯TS303、二氢茉莉酸丙酯(PDJ)及二者复配对大豆光合作用的影响及作用机理。试验结果表明:(1)0.01～1mg.L-1TS303浸种促进大豆干物质积累,以0.1mg.L-1的浓度效果最好,TS303对干物质在地上部和根之间的分配没有明显的影响,1～10mg.L-1PDJ浸种促进干物质积累,以5mg.L-1增幅最大,50和100mg.L-1则抑制干物质积累,1～100mg.L-1PDJ均促进同化物质向根系分配;(2)0.1mg.L-1TS303和5mg.L-1PDJ能增加大豆光合叶面积及净光合速率,增强光合能力,二者混合使用表现出协同效应;(3)0.1mg.L-1TS303和5mg.L-1PDJ及二者复配增加叶绿素含量和提高PSⅡ的实际光转化效率(ФPSⅡ),二者对ФPSⅡ的提高途径不同,TS303增加光合淬灭(qP)而对有效光转化效率(Fv′/Fm′)影响不大,PDJ增加Fv′/Fm′而对qP影响不大;(4)0.1mg.L-1TS303和5mg.L-1PDJ及二者复配增加大豆气孔导度、碳酸酐酶活性、RuBPCase含量和活性,增强CO2转运和固定能力;(5)0.1mg.L-1TS303和5mg.L-1PDJ及二者复配增加叶片中蔗糖的含量,提高蔗糖/淀粉比率,加快同化物质的转运,增加根中淀粉含量。总体上,TS303在光能转化和CO2固定方面效果好于PDJ,而PDJ促进同化物质运出效果好于TS303,这可能是二者协同提高大豆光合能力的原因。

The effects and the action mechanisms of long lasting Brassinosteroid （TS303）, Propyl dihydrojasmonate（PDJ） and their mixture on soybean photosynthetic capacity were investigated. The results showed that： （1） 0.01 - 1 mg·L^-1TS303 promofed in dry matters with optimal concentration of 0.1 mg·L^-1, but had no significant effect on distribution between shoot and root. 1 - 100 mg·L^-1 PDJ promoted dry matter distribution to root as indicated by increasing in R/T, PDJ among 1 ~ 10 mg·L^-1 increased in dry matters with optimal concentration of 5 mg·L^-1, while an inhibitory effects occurred when applied at 50 and 100mg·L^-1; （2）Both0.1 mg·L^-1 TS303 and5 mg·L^-1 PDJ promoted leaves areas, net photosynthetic rate and their derivative index photosynthetic capacity, and a synergistic effect occurred when they were applied in combination; （3）0.1 mg·L^-1 TS303 and 5 mg·L^-1 PDJ applied alone or in combination all promoted chlorophyll concentrations and PS Ⅱ actual efficiency （ φPS Ⅱ ）, indicating the enhancement of light energy harvest and utilization. TS303 increased φPSⅡ through increasing in photochemical quenching （qP） rather than effectual PS Ⅱ efficiency （Fv＇/Fm＇） just in contrast to PDJ; （4）0.1mg·L^-1 TS303 and 5 mg·L^-1 PDJ applied alone or in combination all increased in stomatal conductance （Gs）, carbonic anhyrase activities, RuBPCase concentrations, and actiwties, indicating the enhancement of CO2 transportation and fixation; （5）0.1mg·L^-1 TS303 and 5 mg·L^-1 PDJ applied alone or in combination all increased in sucrose concentrations and ratios of sucrose to starch in leaves, and increased in starch in root, indicating the amelioration to leaf carbohydrate accumulation and feedback inhibition of photosynthesis. The results suggested that it might be the differential mechanisms of TS303 and PDJ that resulted in the synergistic effect.